A parallel hybrid electric vehicle (HEV) uses two parallel power paths to provide the required torque for moving the vehicle. One of the parallel power paths include an electric motor which receives power from an energy storage device (ESD). The second path typically uses a combustion engine. Regulating the energy supplied from the ESD is essential for the viability of the HEV and to maximize fuel economy. A state of charge (SOC) for the ESD is usually controlled by providing an usage window, which is limited by an upper and a lower SOC value. The usage of ESD energy while operating in this window is not regulated. If the SOC drops below the lower SOC value, a controller causes the engine to recharges the ESD. However, this management method decreases the life of the ESD and may decrease the fuel economy performance of the vehicle.